This is scientific American 62nd Science. I'm Joshua Rappler.

New technology is putting the focus on rarely witnessed aggression between two of the fiercest predators in North America. on Recently, researchers didn't know how these formidable predators interacted.

To improve their understanding of these potential heavyweight matches,

scientists set up motion sensitive cameras in British Columbia,

where both species are increasing in number.

The researchers rigged the countryside so that black bears wandering the shorelines of Vancouver

Island would trigger the playing of recorded sounds of Cougar growls over loudspeakers.

Video cameras captured the Bears reactions, which were not timid.

They almost invariably approached the sound source, and in many cases did so in sort of an aggressive manner.

Justin Serasi, an environmental studies researcher at the University of California

in Santa Cruz involved with the research.

Disagressive behavior manifested in different ways.

Mother Bears were the feistiest, with six moms actually charging the cougar sounds and one even biting a speaker.

On the other hand, solitary bears moved towards the speakers making a huffing noise, often associated with aggression.

Serraisi says that the cougar sounds could represent an easy opportunity for the bears to make a food heist. Cougars in the area often cash the seals and sea lions

they kill and come back to them for days, but bears will seek these meals out, driving the big cats away from their leftovers.

The research is in the journal Ethology.

The findings help researchers get a better idea of how populations of large predators will

interact as they recover on the landscape.

There's a lot of research suggesting that, you know, when you've got a whole suite of these

larger apex predators, cougars, wolves and bears, for instance, North America.

They're not all essentially on equal footing.

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